Isoprene-emitting plants are better protected against thermal and oxidative stresses, which is a desirable trait in a climate-changing (drier and warmer) world. Here we compared the ecophysiological performances of transgenic
isoprene-emitting and wild-type non-emitting tobacco plants during
water stress and after re-watering in actual environmental conditions (400 ppm of CO2 and 28 °C of average daily temperature) and in a future climate scenario (600 ppm of CO2 and 32 °C of average daily temperature). Furthermore, we intended to
complement the present knowledge on the mechanisms involved in
isoprene-induced resistance to water deficit stress by examining the
proteome of transgenic
isoprene-emitting and wild-type non-emitting tobacco plants during
water stress and after re-watering in actual climate.
Isoprene emitters maintained higher photosynthesis and electron transport rates under moderate stress in future climate conditions. However, physiological resistance to
water stress in the
isoprene-emitting plants was not as marked as expected in actual climate conditions, perhaps because the stress developed rapidly. In actual climate,
isoprene emission capacity affected the tobacco proteomic profile, in particular by upregulating
proteins associated with stress protection. Our results strengthen the hypothesis that
isoprene biosynthesis is related to metabolic changes at the gene and
protein levels involved in the activation of general stress defensive mechanisms of plants.